2021-09-14 14:04:23

by Sven Peter

[permalink] [raw]
Subject: [PATCH v2 1/3] usb: typec: tipd: Don't read/write more bytes than required

tps6598x_block_read/write always read 65 bytes of data even when much
less is required when I2C_FUNC_I2C is used. Reduce this to the correct
number.

Signed-off-by: Sven Peter <[email protected]>
---
no changes for v2

drivers/usb/typec/tipd/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index 21b3ae25c76d..c18ec3785592 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -123,7 +123,7 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
if (!tps->i2c_protocol)
return regmap_raw_read(tps->regmap, reg, val, len);

- ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data));
+ ret = regmap_raw_read(tps->regmap, reg, data, len + 1);
if (ret)
return ret;

@@ -145,7 +145,7 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
data[0] = len;
memcpy(&data[1], val, len);

- return regmap_raw_write(tps->regmap, reg, data, sizeof(data));
+ return regmap_raw_write(tps->regmap, reg, data, len + 1);
}

static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val)
--
2.25.1


2021-09-14 14:04:58

by Sven Peter

[permalink] [raw]
Subject: [PATCH v2 3/3] usb: typec: tipd: Remove WARN_ON in tps6598x_block_read

Calling tps6598x_block_read with a higher than allowed len can be
handled by just returning an error. There's no need to crash systems
with panic-on-warn enabled.

Signed-off-by: Sven Peter <[email protected]>
---
v1 -> v2:
- added this patch to also remove the WARN_ON in tps6598x_block_read
as suggested by greg k-h

drivers/usb/typec/tipd/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index 8c79ba17a157..93e56291f0cf 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -117,7 +117,7 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
u8 data[TPS_MAX_LEN + 1];
int ret;

- if (WARN_ON(len + 1 > sizeof(data)))
+ if (len + 1 > sizeof(data))
return -EINVAL;

if (!tps->i2c_protocol)
--
2.25.1

2021-09-14 14:05:34

by Sven Peter

[permalink] [raw]
Subject: [PATCH v2 2/3] usb: typec: tipd: Add an additional overflow check

tps6598x_block_read already checks for the maximum length of the read
but tps6598x_block_write does not. Add the symmetric check there as
well.

Signed-off-by: Sven Peter <[email protected]>
---
v1 -> v2:
- removed the WARN_ON to not crash machines running with panic-on-warn
as pointed out by greg k-h

drivers/usb/typec/tipd/core.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index c18ec3785592..8c79ba17a157 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
{
u8 data[TPS_MAX_LEN + 1];

+ if (len + 1 > sizeof(data))
+ return -EINVAL;
+
if (!tps->i2c_protocol)
return regmap_raw_write(tps->regmap, reg, val, len);

--
2.25.1

2021-09-15 07:23:53

by Heikki Krogerus

[permalink] [raw]
Subject: Re: [PATCH v2 1/3] usb: typec: tipd: Don't read/write more bytes than required

On Tue, Sep 14, 2021 at 04:02:33PM +0200, Sven Peter wrote:
> tps6598x_block_read/write always read 65 bytes of data even when much
> less is required when I2C_FUNC_I2C is used. Reduce this to the correct
> number.
>
> Signed-off-by: Sven Peter <[email protected]>

Reviewed-by: Heikki Krogerus <[email protected]>

> ---
> no changes for v2
>
> drivers/usb/typec/tipd/core.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 21b3ae25c76d..c18ec3785592 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -123,7 +123,7 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
> if (!tps->i2c_protocol)
> return regmap_raw_read(tps->regmap, reg, val, len);
>
> - ret = regmap_raw_read(tps->regmap, reg, data, sizeof(data));
> + ret = regmap_raw_read(tps->regmap, reg, data, len + 1);
> if (ret)
> return ret;
>
> @@ -145,7 +145,7 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
> data[0] = len;
> memcpy(&data[1], val, len);
>
> - return regmap_raw_write(tps->regmap, reg, data, sizeof(data));
> + return regmap_raw_write(tps->regmap, reg, data, len + 1);
> }
>
> static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val)
> --
> 2.25.1

thanks,

--
heikki

2021-09-15 07:23:53

by Heikki Krogerus

[permalink] [raw]
Subject: Re: [PATCH v2 2/3] usb: typec: tipd: Add an additional overflow check

On Tue, Sep 14, 2021 at 04:02:34PM +0200, Sven Peter wrote:
> tps6598x_block_read already checks for the maximum length of the read
> but tps6598x_block_write does not. Add the symmetric check there as
> well.
>
> Signed-off-by: Sven Peter <[email protected]>

Reviewed-by: Heikki Krogerus <[email protected]>

> ---
> v1 -> v2:
> - removed the WARN_ON to not crash machines running with panic-on-warn
> as pointed out by greg k-h
>
> drivers/usb/typec/tipd/core.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index c18ec3785592..8c79ba17a157 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
> {
> u8 data[TPS_MAX_LEN + 1];
>
> + if (len + 1 > sizeof(data))
> + return -EINVAL;
> +
> if (!tps->i2c_protocol)
> return regmap_raw_write(tps->regmap, reg, val, len);
>
> --
> 2.25.1

thanks,

--
heikki

2021-09-15 07:26:31

by Heikki Krogerus

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] usb: typec: tipd: Remove WARN_ON in tps6598x_block_read

On Tue, Sep 14, 2021 at 04:02:35PM +0200, Sven Peter wrote:
> Calling tps6598x_block_read with a higher than allowed len can be
> handled by just returning an error. There's no need to crash systems
> with panic-on-warn enabled.
>
> Signed-off-by: Sven Peter <[email protected]>

Reviewed-by: Heikki Krogerus <[email protected]>

> ---
> v1 -> v2:
> - added this patch to also remove the WARN_ON in tps6598x_block_read
> as suggested by greg k-h
>
> drivers/usb/typec/tipd/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 8c79ba17a157..93e56291f0cf 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -117,7 +117,7 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
> u8 data[TPS_MAX_LEN + 1];
> int ret;
>
> - if (WARN_ON(len + 1 > sizeof(data)))
> + if (len + 1 > sizeof(data))
> return -EINVAL;
>
> if (!tps->i2c_protocol)
> --
> 2.25.1

thanks,

--
heikki